vapor-liquid equilibrium of binary systems containing cyano-based ionic liquids and co2: saft-γ gc eos modeling

The unusual thermodynamic behavior of ionic liquid (il)+co2 mixtures has challenged their theoretical modeling. in this paper, a saft-γ equation-based group contribution method (saft-γ gc eos) is used to predict the vapor-liquid equilibrium (vle) of these mixtures. the binary systems containing co2 and 1-butyl-3-methyl-imidazolium-thiocyanate ([bmim][scn]),1-ethyl-3-methylimidazolium dicyanamide ([emim][dca]), 1-butyl-3-methylimidazolium dicyanamide ([bmim][dca]), 1-hexyl-3-methylimidazolium dicyanamide ([hmim][dca]), 1-ethyl-3-methylimidazolium tricyanomethanide ([emim][tcm]), 1-butyl-3-methylimidazolium tricyanomethanide ([bmim][tcm]) or 1-hexyl-3-methylimidazolium tetracyanoborate ([hmim][tcb]) are divided into the functional groups of co2, cyano-based anion, ch2, ch3 and imidazolium-based cationic head. some new saft-γ parameters are optimized at temperatures from 283.15 to 373.15 k and pressures up to about 20 mpa. the observation of an average error of 1.86% between experimental and estimated bubble pressures indicates the desirable performance of saft-γ gc eos to predict the vle of co2+imidazolium-, cyano-based ionic liquid mixtures.